The present invention relates generally to a signal conditioning method and apparatus and, more particularly, to a method and apparatus communicating between an aircraft and an associated store.
Modern aircraft, such as an F-15E aircraft manufactured by the assignee of the present invention, and the P-3, the S-3 and the F-16 aircraft manufactured by Lockheed Aeronautical Systems Company, are adapted to carry stores. These stores can, for example, include missiles, such as the Joint Direct Attack Munition (JDAM), Walleye missile, the Standoff Land Attack missile (SLAM), the SLAM-ER, the Harpoon missile, and the Maverick missile. A missile is generally mounted to the wing of a host aircraft, typically via disconnectable pylons, such that the aircraft can carry the missile to the vicinity of the target destination prior to its deployment.
Prior to and during deployment of a store, the aircraft and the associated store communicate. For example, signals are bidirectionally transmitted between the aircraft and the store to appropriately configure and launch the store. This prelaunch configuration can include downloading the coordinates of the target and initializing the various sensors of the store. In addition, a store, such as a SLAM missile, can transmit a video image, typically via radio frequency (RF) signals, of the target to the aircraft after deployment so that the flight path of the store can be monitored, and, in some instances, controlled to provide greater targeting accuracy.
In order to provide bidirectional signal transmission between the aircraft and the associated store, a host aircraft typically includes an aircraft controls and displays module under the control of a central computer, or aircraft controller. The aircraft controls and displays module provides an interface by which the crew of the aircraft can monitor and control their flight pattern and can provide armament control, such as to control the deployment of the associated store. The aircraft controls and displays module typically includes both discrete controls, such as toggle switches, as well as a joystick for positioning and selecting a cursor within the associated display. The aircraft controls and displays module also provides the necessary avionics to fly the aircraft and to communicate with other aircraft and ground base control stations.
Both the aircraft and the associated store typically process signals according to a predetermined format. As used herein, format refers not only to the actual configuration of the data structures, but also to the content and order of transmission of the signals. The predetermined formats of the aircraft and the store are oftentimes different. In order to ensure proper signal reception by the host aircraft and the associated store, the signals must thus be provided to the aircraft or store in the predetermined format that the aircraft or store is adapted to process.
Aircraft are typically designed to carry a plurality of stores, some of which may process signals according to the same format as the aircraft, and others which may process signals according to a different format. Many aircraft, such as the F-16 Block 60 aircraft, process signals according to a Mil-Std-1760 format. Certain types of missiles, such as the SLAM-ER missile, the JDAM missile, communicate according to the Mil-Std-1760 format. It is not uncommon, however, for other types of stores associated with the F-16 aircraft to process signals according to a different signal format. Missiles such as the Harpoon Block I missile, the SLAM missile, and the Harpoon Block II missile, communicate according to a MK 82 data format. In this regard, the MK 82 and the Mil-Std-1760 formats are different, not only in their respective data structures, but also in the physical connections required for their respective interfaces.
To facilitate the communication between the aircraft and the stores that process signals according to a different format, these stores are coupled to a tailored electronics or avionics system. This avionics system, generally referred to as a weapon interface system (WIS), serves as an interface between the aircraft, specifically the aircraft controller, and the store. With respect to Harpoon Block I missiles, which process signals according to the MK 82 format, a device such as a Harpoon Interface Adapter Kit (HIAK) may generally serve as an interface between the missile and aircraft such as the F-16 aircraft, wired for carriage of 1760 type stores. The HIAK typically receives commands from the aircraft controller according to the 1760 format and translates these commands to provide MK 82 formatted data usable by Harpoon Block I missiles. In addition, the HIAK controls and provides launch power to the aircraft ejectors which eject the Harpoon from the aircraft.
Whereas the HIAK is an adequate apparatus for allowing a 1760 type aircraft to communicate with an MK 82 type Harpoon Block I missile, it has drawbacks. First, the HIAK only supports one MK 82 data format data rate transfer. In this regard, various Harpoon missiles communicate according to the MK 82 data format at different transfer rates. For example, Harpoon Block I missiles use a 100 KHz clock strobe to transmit a 16-bit data word plus a checksum bit in 1700 microseconds, whereas as Harpoon Block II missiles use a 100-300 KHZ clock strobe to transmit a 16 bit data word plus the parity bit in 300 microseconds. Typically, conventional HIAKs translate commands into MK 82 format at only one set transfer rate, typically that of the Harpoon Block I missile. In this regard, the HIAK cannot not support multiple MK 82 data format transfer rates, such as that of both the Harpoon Block I and Harpoon Block II missiles.
Second, the HIAK typically comprises a separate electronic box and set of cables, mounted on a pylon or launch platform and physically detachable from the aircraft to facilitate interchangeability and maintainability. In this regard, the HIAK generally requires an unnecessarily large amount of space on the aircraft and adds undesirable weight to the aircraft. Additionally, because of the number and type of discrete components that make up the HIAK, the HIAK is generally a very expensive interface. Also, because of the complexity of the HIAK, it can be very hard to connect and disconnect from the aircraft as the types of stores attached to the aircraft change. As such, the HIAK missionizes the aircraft by requiring a dedicated aircraft to perform separate missions depending on the desired type of store for the mission.
In light of the foregoing background, the present invention provides an improved signal conditioning element that provides expanded formatting function to add compatibility for the various transfer rates of the MK 82 data format. Additionally, the signal conditioning element of the present invention can be implemented in an application specific integrated circuit (ASIC). In this regard, the signal conditioning element provides signal conditioning between the aircraft and store in a manner that is less expensive than the conventional HIAK, and requires less space and weight. Also, by requiring less space, the signal conditioning element of the present invention can be integrated into a store umbilical that couples the aircraft and the store, or into an aircraft pylon wiring. As such, the signal conditioning element can be easily installed and changed to accommodate different types of stores, thereby eliminating the missionizing associated with conventional HIAKs. According to one embodiment, the present invention provides a signal conditioning system for translating communications between an aircraft and an associated store. The system includes a store umbilical element that electrically and mechanically couples the aircraft and the store, and facilitates communications between the aircraft and associated store. The store umbilical element includes an aircraft connector and a store connector. The aircraft connector is electrically connected to the aircraft and directs communications to and from the aircraft according to a first predetermined format, such as a Mil-Std-1760 format, at a first predefined transfer rate. And the store connector is electrically connected to the store and directs communications to and from the store according to a second predetermined format, such as a MK 82 Digital Data Bus format, at at least one second transfer rate.
The system also includes a signal conditioning element comprising an ASIC electrically connected between the aircraft connector and the store connector of the store umbilical element. The signal conditioning element includes a translation element located between the aircraft and the store connectors for receiving first predetermined format communications from the aircraft connector at the first predefined bit rate and thereafter outputting corresponding second predetermined format communications to the store connector at at least one second transfer rate. Conversely, the translation element is also capable of receiving second predetermined format communications from the store connector at at least one second transfer rate and thereafter outputting corresponding first predetermined format communications to the aircraft connector at the first predefined bit rate. To direct communications between the aircraft connector and the store connector via the translation element, the system additionally includes a processing element. According to one embodiment, the processing element is capable of selecting the second transfer rate based upon the associated store. And in a further embodiment, the processing element is capable of controlling the translation element based on the selected second transfer rate.
According to another embodiment, the translation element includes a first formatting element, a second formatting element and a memory element electrically connected between the first and second formatting elements. In this embodiment, the first formatting element, such as a first encoder and a first decoder, is capable of receiving first predetermined format communications from the aircraft connector at the first predefined transfer rate, encoding the first predetermined format communications and thereafter transmitting the encoded communications. The first formatting element is also capable of receiving encoded communications, decoding the encoded communications into first predetermined format communications and thereafter transmitting the first predetermined format communications to the aircraft connector at the first predefined transfer rate.
Similar to the first formatting element, the second formatting element, such as a second encoder and a second decoder, is capable of receiving second predetermined format communications from the store connector at at least one second transfer rate, encoding the second predetermined format communications and thereafter transmitting the encoded communications. Additionally, the second formatting element is capable of receiving encoded communications, decoding the encoded communications into second predetermined format communications and thereafter transmitting the second predetermined format communications to the store connector at at least one second transfer rate.
The memory element, which is electrically connected between the first and the second formatting elements, is capable of receiving encoded communications from the first formatting element, storing the encoded communications and thereafter transmitting the encoded communications to said second formatting element. Conversely, the memory element is also capable of receiving encoded communications from the second formatting element, storing the encoded communications and thereafter transmitting the encoded communications to the first formatting element.
According to another embodiment, the signal conditioning element further includes an aircraft communications interface electrically connected between the aircraft connector and the translation element. The aircraft communications interface includes at least one transmitter for transmitting first predetermined format communications to the aircraft at the first predefined transfer rate, and at least one receiver for receiving first predetermined format communications from the aircraft at the first predefined transfer rate. Additionally, the aircraft communications interface includes an address element for receiving addressing information from the aircraft associated with the store.
Therefore, the present invention provides greater formatting functionality in a less expensive and generally smaller and lighter signal conditioning element than a conventional HIAK. Because the signal conditioning element can be implemented in an ASIC, the signal conditioning element of the present invention can also be integrated into a store umbilical cable that couples the aircraft and the store, or into an aircraft pylon wiring. In this regard, the signal conditioning element can be easily installed and changed to accommodate different types of stores.